Final answer:
The allowable ampacity for five number 10 AWG current-carrying conductors in a raceway at 70°F would typically be derated according to NEC guidelines. For five conductors, assuming an 80% derating factor, the ampacity per conductor is typically 24 amperes.
Step-by-step explanation:
If five number 10 AWG current-carrying conductors are installed in a raceway where the ambient temperature is 70°F, the allowable ampacity needs to be calculated as per the National Electrical Code (NEC). According to NEC tables, a single 10 AWG copper conductor has an ampacity of 30 amperes at 70°F. When multiple conductors are installed in a raceway, the ampacity of each conductor must be derated to account for the increased heat due to the proximity of the other conductors.
The NEC provides a table for adjusting the ampacity for more than three current-carrying conductors in a raceway. However, since the ambient temperature is 70°F, which is the same as the temperature for which the standard ampacity is rated, no further adjustment for temperature is necessary unless the temperature were to be higher. The derating factor for five conductors from the NEC would be applied to the base ampacity of 30 amperes. If we assume a common derating factor of 80%, the derated ampacity for each conductor would be 30 A × 0.80 = 24 amperes. It is important to check the latest NEC code for the exact derating percentage.